Suzuki GSXR Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
Hey guys I have an 07 750 With a C41 code. My fuel pump still primes and the bike cranks it just won’t start. It had the little bar at the top which based on the service manual I’m assuming it means it falls in the “H” portion of the service manual. The relay ticks and I have verified I don’t have any ECU issues, any ideas?
 

·
Registered
Joined
·
2,008 Posts
Ignore the hash mark for now. Most likely it's high because the bike isn't started and high idle is active and the high reading is expected.

If the pump is priming but you're getting the code, it's either wiring or the ECM. The ECM engages the relay by grounding it on Y/B wire going to pin 39 on the ECM. We know that's good because your pump primes. The relay provides power to the pump, so we know everything from the battery to the pump, and from the pump to ground is good. The ECM can tell if the pump is getting power by watching the voltage on the Y/R wire attached to pin 33.

First thing I would do is disconnect the ECM and the fuel pump and check continuity from the pump to the ECM on the Y/R wire.
 

·
Super Moderator
Joined
·
8,889 Posts
Welcome. I have not worked on that problem and can't remember the last time I saw someone with that code.
Here is the page from the service manual which explains what might trigger the fault.

The pump cycling for a few seconds with key on is interesting and says everything is good.

Is the pump running when you run the starter? It can be hard to hear so put your ear to the tank.
293467
 

·
Registered
Joined
·
3 Posts
Discussion Starter #4
Ok so long story short I’m doing some minor tune ups (oil change, spark plugs, ect) on my older brothers bike. This is important because he has the same exact bike as me. I plugged my ECU into his bike and there were no codes. I also took his relay and put it on my bike (with my ECU back in). All the codes were gone and the bike seemed to be just fine. It was 12am when I did this so unfortunately I did not start the bike.

I’m going to try and get a new relay and see if that works. I have a feeling there’s a short in the harness too but I’ll just have to see when I get the new relay in guess. Also keep in mid the bike was running and then just stopped (this is why I think Theres a short potentially blowing the relay)

Thank you guys for all your help so far!
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
Ok so long story short I’m doing some minor tune ups (oil change, spark plugs, ect) on my older brothers bike. This is important because he has the same exact bike as me. I plugged my ECU into his bike and there were no codes. I also took his relay and put it on my bike (with my ECU back in). All the codes were gone and the bike seemed to be just fine. It was 12am when I did this so unfortunately I did not start the bike.

I’m going to try and get a new relay and see if that works. I have a feeling there’s a short in the harness too but I’ll just have to see when I get the new relay in guess. Also keep in mid the bike was running and then just stopped (this is why I think Theres a short potentially blowing the relay)

Thank you guys for all your help so far!
Update on this, I tried the other relay and after a few seconds of cranking the F1 code came back on, every time I stop cranking the fuel pump primes and it’s hard to tell if it’s running while the bike is cranking. Still no start, I’ll be checking continuity between the ecu and fuel pump later
 

·
Super Moderator
Joined
·
8,889 Posts
every time I stop cranking the fuel pump primes
This is interesting. It sounds like the ECM is rebooting after you stop cranking.

What is the battery voltage when the ignition is on and also while you are cranking the engine?
 
1 - 6 of 6 Posts
Top